Systems have been proposed for recognizing a gesture made by an operator to operate a device positioned away from the operator inside a moving platform. In these kind of systems, it is important to make the operator grasp a spatial position in which a gesture is to be made, because it is required to correctly recognize the gesture for an operation.
For example, Patent reference 1 discloses a system in which a virtual image of an operation system such as an operation switch and/or a button is displayed in a space by using hologram technology or the like, and a gesture made against the virtual image is recognized as an operation to the device. In this system, a gesture can be made in the situation as if the virtual image displayed in the space appears as a real operation system of a device to be operated. Therefore, an operator can easily grasp that the position where the virtual image is displayed is the spatial position in which a gesture is to be made.
Furthermore, in an invention disclosed in Patent reference 2, when a finger of an operator is detected in a space on the straight line connecting between a viewpoint position of an operator and an operation object, it is recognized that the operation object is being operated. This enables the operator to grasp a spatial position in which a gesture is to be made, based on a three-dimensional positional relation between the viewpoint and the operation object.